Ответ:

  1. \(800 + 120 - 860 + 920 = 920 - 860 + 920 = 60 + 920 = 980\).
  2. \(720 - 290 + 570 - 650 = 430 + 570 - 650 = 1000 - 650 = 350\).
  3. \(960 - 490 + 330 - 580 = 470 + 330 - 580 = 800 - 580 = 220\).
  4. \(490 : 70 = 7\).
  5. \(800 : 20 = 40\).
  6. \(710 : 710 = 1\).
  7. \(0 : 1000 = 0\).

Ответ: 980; 350; 220; 7; 40; 1; 0.